Todd Poynor | 21b36ea | 2011-07-01 17:19:56 -0700 | [diff] [blame] | 1 | /* |
| 2 | * otg-wakelock.c |
| 3 | * |
| 4 | * Copyright (C) 2011 Google, Inc. |
| 5 | * |
| 6 | * This software is licensed under the terms of the GNU General Public |
| 7 | * License version 2, as published by the Free Software Foundation, and |
| 8 | * may be copied, distributed, and modified under those terms. |
| 9 | * |
| 10 | * This program is distributed in the hope that it will be useful, |
| 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | * GNU General Public License for more details. |
| 14 | * |
| 15 | */ |
| 16 | |
| 17 | #include <linux/kernel.h> |
| 18 | #include <linux/device.h> |
Arve Hjønnevåg | 7369345 | 2012-11-26 16:09:13 -0800 | [diff] [blame] | 19 | #include <linux/err.h> |
Colin Cross | 666167c | 2012-02-01 14:23:15 -0800 | [diff] [blame] | 20 | #include <linux/module.h> |
Todd Poynor | 21b36ea | 2011-07-01 17:19:56 -0700 | [diff] [blame] | 21 | #include <linux/notifier.h> |
Todd Poynor | 21b36ea | 2011-07-01 17:19:56 -0700 | [diff] [blame] | 22 | #include <linux/spinlock.h> |
| 23 | #include <linux/usb/otg.h> |
| 24 | |
Todd Poynor | 2c7e324 | 2011-09-26 20:35:30 -0700 | [diff] [blame] | 25 | #define TEMPORARY_HOLD_TIME 2000 |
| 26 | |
Todd Poynor | 21b36ea | 2011-07-01 17:19:56 -0700 | [diff] [blame] | 27 | static bool enabled = true; |
Benoit Goby | 3f9860a | 2012-05-10 16:41:40 -0700 | [diff] [blame] | 28 | static struct usb_phy *otgwl_xceiv; |
Todd Poynor | 21b36ea | 2011-07-01 17:19:56 -0700 | [diff] [blame] | 29 | static struct notifier_block otgwl_nb; |
| 30 | |
| 31 | /* |
| 32 | * otgwl_spinlock is held while the VBUS lock is grabbed or dropped and the |
Todd Poynor | 2c7e324 | 2011-09-26 20:35:30 -0700 | [diff] [blame] | 33 | * held field is updated to match. |
Todd Poynor | 21b36ea | 2011-07-01 17:19:56 -0700 | [diff] [blame] | 34 | */ |
| 35 | |
| 36 | static DEFINE_SPINLOCK(otgwl_spinlock); |
| 37 | |
| 38 | /* |
| 39 | * Only one lock, but since these 3 fields are associated with each other... |
| 40 | */ |
| 41 | |
| 42 | struct otgwl_lock { |
| 43 | char name[40]; |
Dmitry Shmidt | 48baaa3 | 2017-01-12 12:45:46 -0800 | [diff] [blame] | 44 | struct wakeup_source wakesrc; |
Todd Poynor | 2c7e324 | 2011-09-26 20:35:30 -0700 | [diff] [blame] | 45 | bool held; |
Todd Poynor | 21b36ea | 2011-07-01 17:19:56 -0700 | [diff] [blame] | 46 | }; |
| 47 | |
| 48 | /* |
Todd Poynor | 2c7e324 | 2011-09-26 20:35:30 -0700 | [diff] [blame] | 49 | * VBUS present lock. Also used as a timed lock on charger |
| 50 | * connect/disconnect and USB host disconnect, to allow the system |
| 51 | * to react to the change in power. |
Todd Poynor | 21b36ea | 2011-07-01 17:19:56 -0700 | [diff] [blame] | 52 | */ |
| 53 | |
| 54 | static struct otgwl_lock vbus_lock; |
| 55 | |
Todd Poynor | 2c7e324 | 2011-09-26 20:35:30 -0700 | [diff] [blame] | 56 | static void otgwl_hold(struct otgwl_lock *lock) |
Todd Poynor | 21b36ea | 2011-07-01 17:19:56 -0700 | [diff] [blame] | 57 | { |
Todd Poynor | 2c7e324 | 2011-09-26 20:35:30 -0700 | [diff] [blame] | 58 | if (!lock->held) { |
Dmitry Shmidt | 48baaa3 | 2017-01-12 12:45:46 -0800 | [diff] [blame] | 59 | __pm_stay_awake(&lock->wakesrc); |
Todd Poynor | 2c7e324 | 2011-09-26 20:35:30 -0700 | [diff] [blame] | 60 | lock->held = true; |
Todd Poynor | 21b36ea | 2011-07-01 17:19:56 -0700 | [diff] [blame] | 61 | } |
| 62 | } |
| 63 | |
Todd Poynor | 2c7e324 | 2011-09-26 20:35:30 -0700 | [diff] [blame] | 64 | static void otgwl_temporary_hold(struct otgwl_lock *lock) |
| 65 | { |
Dmitry Shmidt | 48baaa3 | 2017-01-12 12:45:46 -0800 | [diff] [blame] | 66 | __pm_wakeup_event(&lock->wakesrc, TEMPORARY_HOLD_TIME); |
Todd Poynor | 2c7e324 | 2011-09-26 20:35:30 -0700 | [diff] [blame] | 67 | lock->held = false; |
| 68 | } |
| 69 | |
Todd Poynor | 21b36ea | 2011-07-01 17:19:56 -0700 | [diff] [blame] | 70 | static void otgwl_drop(struct otgwl_lock *lock) |
| 71 | { |
Todd Poynor | 2c7e324 | 2011-09-26 20:35:30 -0700 | [diff] [blame] | 72 | if (lock->held) { |
Dmitry Shmidt | 48baaa3 | 2017-01-12 12:45:46 -0800 | [diff] [blame] | 73 | __pm_relax(&lock->wakesrc); |
Todd Poynor | 2c7e324 | 2011-09-26 20:35:30 -0700 | [diff] [blame] | 74 | lock->held = false; |
Todd Poynor | 21b36ea | 2011-07-01 17:19:56 -0700 | [diff] [blame] | 75 | } |
| 76 | } |
| 77 | |
Todd Poynor | 2c7e324 | 2011-09-26 20:35:30 -0700 | [diff] [blame] | 78 | static void otgwl_handle_event(unsigned long event) |
Todd Poynor | 21b36ea | 2011-07-01 17:19:56 -0700 | [diff] [blame] | 79 | { |
| 80 | unsigned long irqflags; |
| 81 | |
Todd Poynor | 21b36ea | 2011-07-01 17:19:56 -0700 | [diff] [blame] | 82 | spin_lock_irqsave(&otgwl_spinlock, irqflags); |
| 83 | |
Todd Poynor | 2c7e324 | 2011-09-26 20:35:30 -0700 | [diff] [blame] | 84 | if (!enabled) { |
| 85 | otgwl_drop(&vbus_lock); |
| 86 | spin_unlock_irqrestore(&otgwl_spinlock, irqflags); |
| 87 | return; |
| 88 | } |
| 89 | |
Todd Poynor | 21b36ea | 2011-07-01 17:19:56 -0700 | [diff] [blame] | 90 | switch (event) { |
| 91 | case USB_EVENT_VBUS: |
| 92 | case USB_EVENT_ENUMERATED: |
Todd Poynor | 2c7e324 | 2011-09-26 20:35:30 -0700 | [diff] [blame] | 93 | otgwl_hold(&vbus_lock); |
Todd Poynor | 21b36ea | 2011-07-01 17:19:56 -0700 | [diff] [blame] | 94 | break; |
| 95 | |
| 96 | case USB_EVENT_NONE: |
| 97 | case USB_EVENT_ID: |
| 98 | case USB_EVENT_CHARGER: |
Todd Poynor | 2c7e324 | 2011-09-26 20:35:30 -0700 | [diff] [blame] | 99 | otgwl_temporary_hold(&vbus_lock); |
Todd Poynor | 21b36ea | 2011-07-01 17:19:56 -0700 | [diff] [blame] | 100 | break; |
| 101 | |
| 102 | default: |
| 103 | break; |
| 104 | } |
| 105 | |
| 106 | spin_unlock_irqrestore(&otgwl_spinlock, irqflags); |
Todd Poynor | 2c7e324 | 2011-09-26 20:35:30 -0700 | [diff] [blame] | 107 | } |
| 108 | |
| 109 | static int otgwl_otg_notifications(struct notifier_block *nb, |
| 110 | unsigned long event, void *unused) |
| 111 | { |
| 112 | otgwl_handle_event(event); |
Todd Poynor | 21b36ea | 2011-07-01 17:19:56 -0700 | [diff] [blame] | 113 | return NOTIFY_OK; |
| 114 | } |
| 115 | |
Todd Poynor | 21b36ea | 2011-07-01 17:19:56 -0700 | [diff] [blame] | 116 | static int set_enabled(const char *val, const struct kernel_param *kp) |
| 117 | { |
Todd Poynor | 21b36ea | 2011-07-01 17:19:56 -0700 | [diff] [blame] | 118 | int rv = param_set_bool(val, kp); |
| 119 | |
| 120 | if (rv) |
| 121 | return rv; |
| 122 | |
Todd Poynor | 2c7e324 | 2011-09-26 20:35:30 -0700 | [diff] [blame] | 123 | if (otgwl_xceiv) |
| 124 | otgwl_handle_event(otgwl_xceiv->last_event); |
Todd Poynor | 21b36ea | 2011-07-01 17:19:56 -0700 | [diff] [blame] | 125 | |
Todd Poynor | 21b36ea | 2011-07-01 17:19:56 -0700 | [diff] [blame] | 126 | return 0; |
| 127 | } |
| 128 | |
| 129 | static struct kernel_param_ops enabled_param_ops = { |
| 130 | .set = set_enabled, |
| 131 | .get = param_get_bool, |
| 132 | }; |
| 133 | |
| 134 | module_param_cb(enabled, &enabled_param_ops, &enabled, 0644); |
| 135 | MODULE_PARM_DESC(enabled, "enable wakelock when VBUS present"); |
| 136 | |
| 137 | static int __init otg_wakelock_init(void) |
| 138 | { |
Todd Poynor | 2c7e324 | 2011-09-26 20:35:30 -0700 | [diff] [blame] | 139 | int ret; |
Arve Hjønnevåg | 7369345 | 2012-11-26 16:09:13 -0800 | [diff] [blame] | 140 | struct usb_phy *phy; |
Todd Poynor | 21b36ea | 2011-07-01 17:19:56 -0700 | [diff] [blame] | 141 | |
Arve Hjønnevåg | 7369345 | 2012-11-26 16:09:13 -0800 | [diff] [blame] | 142 | phy = usb_get_phy(USB_PHY_TYPE_USB2); |
Todd Poynor | 21b36ea | 2011-07-01 17:19:56 -0700 | [diff] [blame] | 143 | |
Arve Hjønnevåg | 7369345 | 2012-11-26 16:09:13 -0800 | [diff] [blame] | 144 | if (IS_ERR(phy)) { |
Benoit Goby | 3f9860a | 2012-05-10 16:41:40 -0700 | [diff] [blame] | 145 | pr_err("%s: No USB transceiver found\n", __func__); |
Arve Hjønnevåg | 7369345 | 2012-11-26 16:09:13 -0800 | [diff] [blame] | 146 | return PTR_ERR(phy); |
Todd Poynor | 21b36ea | 2011-07-01 17:19:56 -0700 | [diff] [blame] | 147 | } |
Arve Hjønnevåg | 7369345 | 2012-11-26 16:09:13 -0800 | [diff] [blame] | 148 | otgwl_xceiv = phy; |
Todd Poynor | 21b36ea | 2011-07-01 17:19:56 -0700 | [diff] [blame] | 149 | |
Todd Poynor | 2c7e324 | 2011-09-26 20:35:30 -0700 | [diff] [blame] | 150 | snprintf(vbus_lock.name, sizeof(vbus_lock.name), "vbus-%s", |
| 151 | dev_name(otgwl_xceiv->dev)); |
Dmitry Shmidt | 48baaa3 | 2017-01-12 12:45:46 -0800 | [diff] [blame] | 152 | wakeup_source_init(&vbus_lock.wakesrc, vbus_lock.name); |
Todd Poynor | 2c7e324 | 2011-09-26 20:35:30 -0700 | [diff] [blame] | 153 | |
| 154 | otgwl_nb.notifier_call = otgwl_otg_notifications; |
Benoit Goby | 3f9860a | 2012-05-10 16:41:40 -0700 | [diff] [blame] | 155 | ret = usb_register_notifier(otgwl_xceiv, &otgwl_nb); |
Todd Poynor | 2c7e324 | 2011-09-26 20:35:30 -0700 | [diff] [blame] | 156 | |
| 157 | if (ret) { |
Benoit Goby | 3f9860a | 2012-05-10 16:41:40 -0700 | [diff] [blame] | 158 | pr_err("%s: usb_register_notifier on transceiver %s" |
Todd Poynor | 2c7e324 | 2011-09-26 20:35:30 -0700 | [diff] [blame] | 159 | " failed\n", __func__, |
| 160 | dev_name(otgwl_xceiv->dev)); |
| 161 | otgwl_xceiv = NULL; |
Dmitry Shmidt | 48baaa3 | 2017-01-12 12:45:46 -0800 | [diff] [blame] | 162 | wakeup_source_trash(&vbus_lock.wakesrc); |
Todd Poynor | 2c7e324 | 2011-09-26 20:35:30 -0700 | [diff] [blame] | 163 | return ret; |
| 164 | } |
| 165 | |
| 166 | otgwl_handle_event(otgwl_xceiv->last_event); |
| 167 | return ret; |
Todd Poynor | 21b36ea | 2011-07-01 17:19:56 -0700 | [diff] [blame] | 168 | } |
| 169 | |
| 170 | late_initcall(otg_wakelock_init); |